There doesn't seem to be anything directly illegal about it. The fact that its name is Genesect and not written in Japanese could be a clue that it's hacked, however unless I'm mistaken, it's possible to RNG the TID and SID to get a save file where the Genesect is nicknamable.
However from what I remember, that event Genesect has been hacked and traded around quite a lot in the past, so unless there's solid evidence that the Genesect was originally obtained and RNG'd by someone very trustworthy, I consider it highly likely to be hacked. (it could also be worth reporting to a staff member in the Wi-Fi room, if you got it from a trade there)

There doesn't seem to be anything directly illegal about it. The fact that its name is Genesect and not written in Japanese could be a clue that it's hacked, however unless I'm mistaken, it's possible to RNG the TID and SID to get a save file where the Genesect is nicknamable.
However from what I remember, that event Genesect has been hacked and traded around quite a lot in the past, so unless there's solid evidence that the Genesect was originally obtained and RNG'd by someone very trustworthy, I consider it highly likely to be hacked. (it could also be worth reporting to a staff member in the Wi-Fi room, if you got it from a trade there)

Don't you dare say you'd rather lose

From the details you provided: no, it seems to be legal.
The main point that leads to why I'd consider it hacked is that it's 6IV and has a relatively sketchy origin, along with the fact that it was a popular Pokemon to hack.
I definitely wouldn't trade it around on these forums or in the Wi-Fi room on PS!, but since there doesn't seem to be anything directly illegal about the Genesect, I suppose you could keep it to use in Wi-Fi battles where legal hacks are allowed.

#GiveWaluigiHisOwnGame

That Genesect behaves weirdly in terms of RNG (to the point where several experienced RNGers have failed to do it properly), so that combined with what Sondero said about it being a frequently hacked 'mon lead me to err on the side of caution and call it a likely hack, unless it can be traced back to a reputable source.

I've had this Eevee for quite a while back in Pokemon Alpha Sapphire and it was used to get myself a Sylveon about a couple of years ago. But...looking back at it now before this warning of suspicious Wonder Traded Pokemon, I had to do a hack check now.

Nothing about that is suspicious, imo. Everything seems correct, and the order of ribbons is not something that is changeable by hacking - it's fixed, so the order of ribbons adds no suspicion at all. Overall it certainly looks legal to me :)

#GiveWaluigiHisOwnGame

It looks like a regular playthrough Yveltal, but with modified IVs to make them... worse?
Anyway, gen 6 Legendaries must have a minimum of 3 IVs that are 31, so if what you've said is true then it's a hack/edit and should not be traded here.

It looks like a regular playthrough Yveltal, but with modified IVs to make them... worse?
Anyway, gen 6 Legendaries must have a minimum of 3 IVs that are 31, so if what you've said is true then it's a hack/edit and should not be traded here.

I heard that same parents have a 50/50 chance to pass down each ball. Is this true? Because if it is, then this is outdated:

Level, Lure, Moon, Friend, Love, Heavy, Fast
Everything that can be captured in HG/SS, excluding those only available through PokéWalker/Bug Catching Contest. These are all incompatible with their Hidden Ability.

I just wanted to add on a few more OTs that shows hacked Pokemon:
* AuSLove.TV or AuSLove.TV E (very bad hacks such as shiny Victinis)
* TomBrownYT
* KAMINO
* RoC (seen a lot of times)

There could be more. These are either Youtubers or twitch users that use Wonder Trade and Link Trade to distribute Hacked Pokemons on Festival Plaza.
I have encountered Shiny DBHA Lugia with OT AuSLove.TV and someone has encountered a Shiny Victini with that OT. Regarding TomBrownYT, he is a Youtuber, and he distributes hacks.

I have been going on Festival Plaza looking out for hacked OTs nowadays. Hopes that this information helps. :)

Back in gen 6 while i was wonder trading I got a shiny 6IV treecko from AuSLove.TV I trained it up to lv.50 and then traded it to sun and moon. After reading through this tread I now assume it's hacked should I just release it or just keep it in my P.C for battles with friends that aren't competitive.

#GiveWaluigiHisOwnGame

Back in gen 6 while i was wonder trading I got a shiny 6IV treecko from AuSLove.TV I trained it up to lv.50 and then traded it to sun and moon. After reading through this tread I now assume it's hacked should I just release it or just keep it in my P.C for battles with friends that aren't competitive.

Yes, it's hacked. Having it on your save and using it in battles with your friends etc won't harm your game in any way, but trying to trade it (or Pokemon bred using it as a parent) here will get you in a spot of bother.

Language: English
Species: Sneasel
OT: Rosa
ID No.: 05595
IVs: 31/31/31/xx/31/31
EVs (optional):
Ability: Keen Eye
Pokemon's name: Sneasel (no nickname)
Gender: Female
Level: 1
Pokeball: Moon Ball
Shiny?: No
Pentagon?: Yes
Moves: Fake Out, Icicle Crash, Ice Shard, Pursuit
Nature: Jolly
Region of origin: Lumiose City
Characteristic: Likes to thrash about
Ribbons: None
Other comments (optional): I was planning on breeding Sneasel for the upcoming Weakness tourny and while rummaging through my PC box within X to see if I had a Sneasel to start the breeding process I happen to find this Pokemon. Now I forgot where I got it from and I seen one instance of this OT/ID combo on Smogon here so I'm wondering if this Sneasel legit and okay to use for breeding.

Language: English
Species: Sneasel
OT: Rosa
ID No.: 05595
IVs: 31/31/31/xx/31/31
EVs (optional):
Ability: Keen Eye
Pokemon's name: Sneasel (no nickname)
Gender: Female
Level: 1
Pokeball: Moon Ball
Shiny?: No
Pentagon?: Yes
Moves: Fake Out, Icicle Crash, Ice Shard, Pursuit
Nature: Jolly
Region of origin: Lumiose City
Characteristic: Likes to thrash about
Ribbons: None
Other comments (optional): I was planning on breeding Sneasel for the upcoming Weakness tourny and while rummaging through my PC box within X to see if I had a Sneasel to start the breeding process I happen to find this Pokemon. Now I forgot where I got it from and I seen one instance of this OT/ID combo on Smogon here so I'm wondering if this Sneasel legit and okay to use for breeding.

Couldn't find any reference to it anywhere, nor could I find anything fundamentally wrong with it. The OT that matched and had the correct IGN was from a TSV hatch, so it's possible that whoever ran that thread might know how to track down the original owner, but I doubt that this individual is active enough for such. It's possible that the OT was listed on Smogon's TSV list (I checked all other TSV Databases), but the list has shed inactive users and is no longer complete and thus OT's from that time period may be hard to find. However, since you don't where it came from, it's probably safer to not use it for breeding, but there's nothing wrong with it, and Moon Ball Sneasel's are common enough.

It is hacked. Shaymin that are in Cherish Balls all have Classic Ribbons. And I'm pretty sure the only way to get Shiny Shaymin is by catching in Diamond/Pearl/Platinum, so it wouldn't be possible to caught in a Cherish Ball.